This relates generally to electronic devices and, more particularly, to electronic devices having touch sensors.
Electronic devices often include touch sensors. For example, cellular telephones often have displays that include capacitive touch sensors. The location of a user's finger or other external object on the display of a cellular telephone can be used to control the operation of the cellular telephone.
A typical capacitive touch sensor for a display has a two-dimensional array of capacitive touch sensor electrodes. The capacitive touch sensor electrodes can be formed from a material such as indium tin oxide that is both conductive and transparent. Signal lines formed from opaque metal traces run around the periphery of the array and are used to convey signals associated with the capacitive touch sensor electrodes.
The central portion of a display contains an array of display pixels for generating images and is sometimes referred to as the active area of the display. The touch sensor array overlaps the array of display pixels in the active area and gathers touch input. Inactive border regions surround the active area. To hide potentially unsightly display components such as the metal signal lines associated with the touch sensor array and display pixel array, the inactive border region can be covered by a bezel or an opaque masking layer such as a layer of black ink. If care is not taken, however, the width of inactive areas of a touch screen display may be considerable. Excessively large borders are generally not aesthetically pleasing and can lead to overly bulky devices.
It would therefore be desirable to be able to provide touch sensors for displays that help minimize the width of inactive borders.